(CBS/AP) RANCHO SANTA MARGARITA, Calif. - The father of Kyndall Jack, a young woman lost for a fifth day in a Southern California wilderness, says she apparently couldn't keep up with her hiking companion as the two tried to make their way out of shoulder-high brush, possibly because of a twisted ankle.

Russ Jack tells the Los Angeles Times Thursday that 19-year-old Nicholas Cendoya shared some information with investigators, despite being dehydrated and very disoriented after being rescued Wednesday night.

Searchers are hunting for the 18-year-old Jack, who's been missing in Cleveland National Forest since Sunday.

Russ Jack says Cendoya believed his friend had already been saved. Cendoya said he hadn't seen her for at least a day.